Roller-Press Apparatus

ABSTRACT

The present disclosure provides a roller-press apparatus, which comprises: an unwinding mechanism around which an electrode plate to be rolled is wound, the electrode plate has a foil and a coating layer, the foil has at least a coated area and a blank foil area, the foil is provided with the coating layer at the coated area and is not provided with the coating layer at the blank foil area; a rolling mechanism; and a stretching mechanism. The stretching mechanism comprises: two guide rollers; and an uneven roller positioned between the two guide rollers, and forming a wrap angle with the two guide rollers, the uneven roller matches the electrode plate in size to allow a protruding portion of the uneven roller to act on the foil at the blank foil area, so as to allow the foil at the blank foil area to be plastically deformed.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to Chinese patent applicationNo. 201410259321.3 filed on Jun. 12, 2014, which is incorporated hereinby reference in its entirety.

TECHNICAL FIELD OF THE PRESENT DISCLOSURE

The present disclosure relates to a field of production equipment of alithium-ion battery, and particularly relates to a roller-pressapparatus.

BACKGROUND OF THE PRESENT DISCLOSURE

A process for preparing an electrode plate of a lithium-ion batterygenerally includes steps of slurrying, coating, drying, rolling,cutting, and the like, although different manufacturers or differentbattery manufacturing processes may be varied, the step of rolling inthe process for preparing the electrode plate is an essential process.The electrode plate achieves a certain compacted density after rolling,which is very important to the improvement of the capacity density ofthe lithium-ion battery. However, after the electrode plate which iscoated is rolled, there is usually a problem that a foil of theelectrode plate wrinkles at a longitudinal edge between each coated areaand an adjacent blank foil area. This is mainly because that, aftercompletion of coating for the electrode plate of the lithium-ionbattery, during the rolling process, the pressure of the press rollerexerted on the coating layer at the coated area would cause the foil atthe coated area to extend in a longitudinal direction, and the foils atthe intermediate blank foil area and the side blank foil areas on bothsides (these are the foil portions at the non-coated area) do not extendbecause no force is exerted on the intermediate blank foil area and theside blank foil areas on both sides (these are the foil portions at thenon-coated area), the foil at the blank foil area restrains the foil atthe coated area from extending, so as to cause that the foil at thelongitudinal edge between the each coated area and the adjacent blankfoil area to wrinkle. In addition, in the production process of theelectrode plate of the lithium-ion battery, the striped coating methodcan improve the coating efficiency and save the production cost, and thenumber and width of the stripes can be varied according to therequirements for the desired electrode plate. However, at present, fordouble roller-structure cold pressing technology adopted with respect tothe striped electrode plate, there is also a problem that the foil ofthe electrode plate wrinkles at the longitudinal edge between the eachcoated area and the adjacent blank foil area.

SUMMARY OF THE PRESENT DISCLOSURE

In view of the problem existing in the background, an object of thepresent disclosure is to provide a roller-press apparatus, which canavoid that the foil of the electrode plate wrinkles at the longitudinaledge between the each coated area and the adjacent blank foil area inthe rolling process of the electrode plate which is coated.

In order to achieve the above object, the present disclosure provides aroller-press apparatus, which comprises: an unwinding mechanism aroundwhich an electrode plate to be rolled is wound, and the unwindingmechanism unwinds the electrode plate to be rolled, the electrode plateto be rolled has a foil and a coating layer provided on at least asurface of the foil, the foil has at least a coated area extending alonga longitudinal direction of the foil and a blank foil area positioned ata side direction of the coated area on the corresponding surfaceprovided with the coating layer, the foil is provided with the coatinglayer at the coated area and is not provided with the coating layer atthe blank foil area; a rolling mechanism comprising a press roller and aback roller which are oppositely provided, and used for rolling theelectrode plate; a winding mechanism winding the electrode plate afterrolled; and a stretching mechanism provided between the rollingmechanism and the winding mechanism. The stretching mechanism comprises:two guide rollers; and an uneven roller positioned between the two guiderollers, and forming a wrap angle with the two guide rollers, the unevenroller matches the electrode plate in size to allow a protruding portionof the uneven roller to act on the foil at the blank foil area, so as toallow the foil at the blank foil area to be plastically deformed.

The present disclosure has the following beneficial effects:

By that the stretching mechanism is provided in the roller-pressapparatus, the foil at the blank foil area is plastically deformed,finally the extension of the foil at the blank foil area is consistentwith the extension of the foil at the coated area, so that the problemin prior art, that the foil of the electrode plate wrinkles at thelongitudinal edge between the each coated area and the adjacent blankfoil area in the process of rolling the electrode plate which is coated,is resolved.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic plan view according to an embodiment of aroller-press apparatus of the present disclosure;

FIG. 2 is a schematic plan view according to an embodiment of theroller-press apparatus of the present disclosure;

FIG. 3 is a schematic plan view according to an embodiment of theroller-press apparatus of the present disclosure;

FIG. 4 is a schematic plan view illustrating an uneven roller accordingto an embodiment of the present disclosure acts on an electrode plate,and the electrode plate is shown in perspective for purposes of clarity;

FIG. 5 is a schematic plan view of the uneven roller of FIG. 4;

FIG. 6 is a cross-sectional view taken along a line X-X of FIG. 5;

FIG. 7 is a perspective view of the electrode plate of FIG. 4.

Reference numerals of the embodiments are represented as follows:

1 unwinding mechanism 2 rolling mechanism  21 press roller  22 backroller 3 winding mechanism 4 guiding roller 5 stretching mechanism  51guide roller  52 uneven roller 521 protruding portion 522 recessingportion  E wrap angle 6 heating element 7 stretching roller pair  71stretching drive roller  72 stretching press roller 8 synchronizingroller pair  81 synchronizing drive roller  82 synchronizing pressroller 9 electrode plate  91 foil 911 coated area 912 intermediate blankfoil area 913 side blank foil area  92 coating layer  L longitudinaldirection

DETAILED DESCRIPTION

Hereinafter a roller-press apparatus according to the present disclosurewill be described in detail in combination with the Figures.

Referring to FIGS. 1-7, a roller-press apparatus according to thepresent disclosure comprises: an unwinding mechanism 1 around which anelectrode plate 9 to be rolled is wound, and the unwinding mechanism 1unwinds the electrode plate 9 to be rolled, the electrode plate 9 to berolled has a foil 91 and a coating layer 92 provided on at least asurface of the foil 91, the foil 91 has at least a coated area 911extending along a longitudinal direction of the foil 91 and a blank foilarea positioned at a side direction of the coated area 911 on thecorresponding surface provided with the coating layer 92, the foil 91 isprovided with the coating layer 92 at the coated area 911 and is notprovided with the coating layer 92 at the blank foil area; a rollingmechanism 2 comprising a press roller 21 and a back roller 22 which areoppositely provided, and used for rolling the electrode plate 9; awinding mechanism 3 winding the electrode plate 9 after rolled; and astretching mechanism 5 provided between the rolling mechanism 2 and thewinding mechanism 3. The stretching mechanism 5 comprises: two guiderollers 51; and an uneven roller 52 positioned between the two guiderollers 51, and forming a wrap angle E with the two guide rollers 51,the uneven roller 52 matches the electrode plate 9 in size to allow aprotruding portion 521 of the uneven roller 52 to act on the foil 91 atthe blank foil area, so as to allow the foil 91 at the blank foil areato be plastically deformed, thereby resolving the problem that the foil91 wrinkles at a longitudinal edge (that is a common boundary) betweenthe each coated area 911 and the adjacent blank foil area.

Here, it should be noted that, the protruding portion 521 of the unevenroller 52 acts on the foil 91 at the blank foil area refers to: (1) whenthe coating layer 92 is only provided on one surface of the foil 91, andwhen the surface of the foil 91 provided with the coating layer 92 facesthe uneven roller 52, the protruding portion 521 of the uneven roller 52acts on the foil 91 at the blank foil area on the surface of the foil 91provided with the coating layer 92; when the surface of the foil 91provided with the coating layer 92 faces away from the uneven roller 52,the protruding portion 521 of the uneven roller 52 acts on the foil 91at an area on a surface of the foil 91 not provided with the coatinglayer 92 and corresponding to the blank foil area on the surface of theabove foil 91 provided with coating layer 92; (2) when two oppositesurfaces of the foil 91 each are provided with the coating layer 92, theprotruding portion 521 of the uneven roller 52 acts on the foil 91 atthe blank foil area on the surface of the foil 91 provided with coatinglayer 92 and facing the uneven roller 52.

Here, it should be further noted that, for the recessing portion 522 ofthe uneven roller 52, when the coating layer 92 is only provided on onesurface of the foil 91, and when the surface of the foil 91 providedwith the coating layer 92 faces the uneven roller 52, the recessingportion 522 of the uneven roller 52 corresponds to and may contact ormay not contact the coating layer 92 at the coated area 911; when thesurface of the foil 91 provided with the coating layer 92 faces awayfrom the uneven roller 52, the recessing portion 522 of the unevenroller 52 may contact or may not contact the foil 91 at an areacorresponding to the coated area 911 on the surface of the foil 91provided with the coating layer 92. When two opposite surfaces of thefoil 91 each are provided with the coating layer 92, there must be onesurface of the foil 91 provided with the coating layer 92 facing theuneven roller 52, in this case, the recessing portion 522 of the unevenroller 52 corresponds and may contact or may not contact the coatinglayer 92 at the coated area 911 on the surface of the foil 91 facing theuneven roller 52.

Preferably, a recessing portion 522 of the uneven roller 52 may contactthe coating layer 92 at the coated area 911 on the surface of the foil91 provided with the coating layer 92 and facing the uneven roller 52,or contact the foil 91 at an area on a surface of the foil 91 notprovided with the coating layer 92 and facing the uneven roller 52 andcorresponding to the coated area 911 on the surface of the foil 91provided with the coating layer 92, so as to effectively prevent thefoil from fracturing which may occur when the protruding portion 521 ofthe uneven roller 52 acts on the foil 91 at the blank foil area.

In an embodiment, the wrap angle E may be 10°˜170°.

In FIG. 7, the foil 91 has two coated areas 911 extending along thelongitudinal direction of the foil 91 and an intermediate blank foilarea 912 between the two adjacent coated areas 911 and two side blankfoil areas 913 at outer sides of all the coated areas 911 on thecorresponding surface provided with the coating layer 92, and herein,the one intermediate blank foil area 912 and the two side blank foilareas 913 are collectively referred to as the blank foil area.

Here, it should be noted that, when the coating layer 92 is onlyprovided on one surface of the foil 91, the press roller 21 or the backroller 22 contacts all the coating layer 92 on the corresponding onesurface but does not contact the foil 91 at the blank foil area; whenthe two surfaces of the foil 91 each are provided with the coating layer92, the press roller 21 and the back roller 22 respectively contact allthe coating layer 92 on the corresponding surface but do not contact thefoil 91 at the blank foil area on the corresponding surface.

Corresponding to FIG. 4 and referring to FIG. 7, in FIG. 4, an electrodeplate 9 to be rolled has a foil 91 and the coating layers 92 provided ontwo opposite surfaces of the foil 91, three protruding portions 521 ofthe uneven roller 52 (from left to right in FIG. 5) respectively act onthe side blank foil area 913, the intermediate blank foil area 912, theside blank foil area 913 (in a sequence from lower left to upper rightin FIG. 7) facing the uneven roller 52 of the foil 91; and the tworecessing portions 522 of the uneven roller 52 respectively correspondto the coating layers 92 at the two coated areas 911, in this case, thetwo recessing portions 522 of the uneven roller 52 may respectivelycontact the coating layers 92 at the two coated areas 911, of course maynot either contact the coating layers 92 at the two coated areas 911,which may be determined based on the actual situation.

Specifically, in the examples as shown in FIGS. 1-7, the electrode plate9 passes through and is rolled by the rolling mechanism 2 in a tensionedstate due to braking force provided by the unwinding mechanism 1 and thewinding mechanism 3, so as to achieve a certain compacted density.Because a thickness of the electrode plate 9 at the coated area 911 isgreater than a thickness at the blank foil area, the coating layer 92 atthe coated area 911 bears the pressure of the press roller 21 and causesthe foil 91 at this area to extend along the longitudinal direction L,and the intermediate blank foil area 912 and the side blank foil area913 do not bear the pressure of the press roller 21, that is the foil 91at the blank foil area does not extend, therefore, the foil 91 at theintermediate blank foil area 912 and the side blank foil area 913 willrestrain the foil 91 at the coated areas 911 from extending, whicheasily causes the foil 91 to wrinkle at the longitudinal edge (that isthe common boundary) between the each coated area 911 and the adjacentblank foil area. The roller-press apparatus of the present disclosureadopts the stretching mechanism 5, the uneven roller 52 of thestretching mechanism 5 allows plastic deformation of the foil 91 at theintermediate blank foil area 912 and the side blank foil area 913, sothat the problem that foil 91 wrinkles at the longitudinal edge betweenthe each coated area 911 and the adjacent blank foil area is resolved.

Referring to FIG. 4, FIG. 5 and FIG. 6, a diameter of the recessingportion 522 of the uneven roller 52 is A, a diameter of the protrudingportion 521 is B, a transition corner is between the adjacent recessingportion 522 and the protruding portion 521 on the same side, a width ofthe recessing portion 522 in the axial direction is C, a width betweenthe outermost positions of corresponding transition corners of twoadjacent protruding portions 521 is D. And, A and B are adjustedaccording to the thickness of the electrode plate 9 (including thethickness of the foil 91 and the thickness of the coating layer 92) andan expected stretch rate, C and D are adjusted according to a width ofthe coated area 911 and a width of the blank foil area. In anembodiment, D−C≦±1 mm. In an embodiment, D−C=0.03 mm˜0.80 mm. In anembodiment, B−A=0.1 mm˜0.5 mm.

In order to allow the foil 91 at the blank foil area to plasticallydeformed better, referring to FIG. 2 and FIG. 3, the roller-pressapparatus according to the present disclosure may further comprises: aheating element 6 for heating the blank foil area of the foil 91 beforethe uneven roller 52 acts on the electrode plate 9. In an embodiment,referring to FIG. 2 and FIG. 3, the heating element 6 may face theelectrode plate 9 and is provided above the electrode plate 9. A heatingtemperature of the heating element 6 may be 50° C.˜300° C., the aboveheating temperature of the heating element 6 is adjusted according to amaterial of the foil 91 of the electrode plate 9 which is actually used.In addition, a position and a width for heating of the heating element 6may be adjusted according to the width of the blank foil area of thefoil 91, so as to ensure appropriate heating for the blank foil area;meanwhile, a height of the heating element 6 distanced from theelectrode plate 9 may also be adjusted, so as to ensure the blank foilarea of the foil 91 to achieve the appropriate heating temperature.

In order to solve the above wrinkling problem better, in an embodiment,the roller-press apparatus according to the present disclosure mayfurther comprise: a stretching roller pair 7 close to the windingmechanism 3 and comprising a stretching drive roller 71 and a stretchingpress roller 72 which are oppositely provided, the stretching pressroller 72 presses the entire electrode plate 9 on the stretching driveroller 71, so as to allow a conveying speed of the electrode plate 9 tobe equal to a speed of the stretching drive roller 71, and the speed ofthe stretching drive roller 71 is greater than a speed of the pressroller 21 of the rolling mechanism 2, so as to allow the electrode plate9 to be stretched in full size by virtue of a speed difference betweenthe stretching drive roller 71 and the press roller 21. After stretchingin full size, because the blank foil area of the foil 9 may beelastically deformed easily (i.e., rebound), the uneven roller 52 actson the foil 9 at the blank foil area after the electrode plate 9 isstretched in full size, so as to achieve better stretching effect.

In order to further improve the stretching effect, in an embodiment, theroller-press apparatus according to the present disclosure may furthercomprise: a synchronizing roller pair 8 close to the rolling mechanism 2and comprising a synchronizing drive roller 81 and a synchronizing pressroller 82 which are oppositely provided, the synchronizing press roller82 presses the entire electrode plate 9 on the synchronizing driveroller 81, so as to allow the conveying speed of the electrode plate 9to be equal to a speed of the synchronizing drive roller 81, and thespeed of the synchronizing drive roller 81 is equal to the speed of thepress roller 21 of the rolling mechanism 2.

In an embodiment, a parallelism difference between an axial line of thesynchronizing drive roller 81 and an axial line of the stretching driveroller 71 is ≦0.1 mm, so as to achieve better stretching effect, andprevent the electrode plate from fracturing.

In an embodiment of the rolling mechanism 2, the press roller 21 and theback roller 22 of the rolling mechanism 2 may be flat steel rollers. Inan embodiment, the roughness, Ra, of the steel roller is ≦0.4, thehardness of the steel roller is ≧65HRC.

In an embodiment of the roller-press apparatus according to the presentdisclosure, the speed of the press roller 21 and/or the synchronizingdrive roller 81 is V1, the speed of the stretching drive roller 71 isV2, and V2=V1*(1+n), and 0<n≦0.100.

In an embodiment, the synchronizing drive roller 81 and the stretchingdrive roller 71 may be steel rollers.

In an embodiment, the synchronizing press roller 82 and the stretchingpress roller 72 may be made of a soft material.

In an embodiment, the synchronizing press roller 82 and the stretchingpress roller 72 may be rubber rollers.

In an embodiment, a frictional force provided by the synchronizing pressroller 82 is greater than 800N, and a frictional force provided by thestretching press roller 72 is greater than 800N.

Here, it should be noted that, in the roller-press apparatus accordingto the present disclosure, the electrode plate 9 may have one coatedarea 911, may also be a striped electrode plate (i.e., having at leasttwo coated areas 911, referring to FIG. 7). Although FIG. 7 shows anelectrode plate 9 having two coated areas 911, but is not limited tothat.

In addition, the roller-press apparatus according to the presentdisclosure may further comprises: a plurality of guiding rollers 4provided between the unwinding mechanism 1 and the winding mechanism 3for guiding and conveying the electrode plate 9.

What is claimed is:
 1. A roller-press apparatus, comprising: anunwinding mechanism (1) around which an electrode plate (9) to be rolledis wound, and the unwinding mechanism (1) unwinding the electrode plate(9) to be rolled, the electrode plate (9) to be rolled having a foil(91) and a coating layer (92) provided on at least a surface of the foil(91), the foil (91) having at least a coated area (911) extending alonga longitudinal direction of the foil (91) and a blank foil areapositioned at a side direction of the coated area (911) on thecorresponding surface provided with the coating layer (92), the foil(91) being provided with the coating layer (92) at the coated area (911)and being not provided with the coating layer (92) at the blank foilarea; a rolling mechanism (2) comprising a press roller (21) and a backroller (22) which are oppositely provided, and used for rolling theelectrode plate (9); a winding mechanism (3) winding the electrode plate(9) after rolled; and a stretching mechanism (5) provided between therolling mechanism (2) and the winding mechanism (3), and comprising: twoguide rollers (51); and an uneven roller (52) positioned between the twoguide rollers (51), and forming a wrap angle (E) with the two guiderollers (51), the uneven roller (52) matching the electrode plate (9) insize to allow a protruding portion (521) of the uneven roller (52) toact on the foil (91) at the blank foil area, so as to allow the foil(91) at the blank foil area to be plastically deformed.
 2. Theroller-press apparatus according to claim 1, wherein a recessing portion(522) of the uneven roller (52) contacts the coating layer (92) at thecoated area (911) on the surface of the foil (91) provided with thecoating layer (92) and facing the uneven roller (52), or contacts thefoil (91) at an area on a surface of the foil (91) not provided with thecoating layer (92) and facing the uneven roller (52) and correspondingto the coated area (911) on the surface of the foil (91) provided withthe coating layer (92).
 3. The roller-press apparatus according to claim1, wherein a diameter of the recessing portion (522) of the unevenroller (52) is A, a diameter of the protruding portion (521) is B, andB−A=0.1 mm˜0.5 mm.
 4. The roller-press apparatus according to claim 1,wherein a transition corner is between adjacent recessing portion (522)and protruding portion (521) on the same side, a width of the recessingportion (522) in an axial direction is C, a width between the outermostpositions of corresponding transition corners of two adjacent protrudingportions (521) is D, and D−C≦±1 mm.
 5. The roller-press apparatusaccording to claim 4, wherein D−C=0.03 mm˜0.80 mm.
 6. The roller-pressapparatus according to claim 1, further comprising: a heating element(6) for heating the blank foil area of the foil (91) before the unevenroller (52) acts on the electrode plate (9).
 7. The roller-pressapparatus according to claim 1, further comprising: a stretching rollerpair (7) close to the winding mechanism (3) and comprising a stretchingdrive roller (71) and a stretching press roller (72) which areoppositely provided, the stretching press roller (72) pressing theentire electrode plate (9) on the stretching drive roller (71), so as toallow a conveying speed of the electrode plate (9) to be equal to aspeed of the stretching drive roller (71), and the speed of thestretching drive roller (71) being greater than a speed of the pressroller (21) of the rolling mechanism (2).
 8. The roller-press apparatusaccording to claim 7, further comprising: a synchronizing roller pair(8) close to the rolling mechanism (2) and comprising a synchronizingdrive roller (81) and a synchronizing press roller (82) which areoppositely provided, the synchronizing press roller (82) pressing theentire electrode plate (9) on the synchronizing drive roller (81), so asto allow the conveying speed of the electrode plate (9) to be equal to aspeed of the synchronizing drive roller (81), and the speed of thesynchronizing drive roller (81) being equal to the speed of the pressroller (21) of the rolling mechanism (2).
 9. The roller-press apparatusaccording to claim 8, wherein a parallelism difference between an axialline of the synchronizing drive roller (81) and an axial line of thestretching drive roller (71) is ≦0.1 mm.
 10. The roller-press apparatusaccording to claim 7, wherein the speed of the press roller (21) and/orthe synchronizing drive roller (81) is V1, the speed of the stretchingdrive roller (71) is V2, and V2=V1*(1+n), and, 0<n≦0.100.
 11. Theroller-press apparatus according to claim 8, wherein the speed of thepress roller (21) and/or the synchronizing drive roller (81) is V1, thespeed of the stretching drive roller (71) is V2, and V2=V1*(1+n), and,0<n≦0.100.